The present invention relates to a slide gate valve or sliding closure unit for use at the nozzle of a vessel containing molten metal and of the type including a housing, a stationary bottom refractory plate fixedly mounted in the housing, and a sliding refractory plate that can be pressed sealingly against the bottom plate by spring means. The sliding plate is supported in an assembly that is movable along guideways of the housing between open and closed positions and that can be swung away from the housing upon release of the spring means.
As a rule, in this type of slide gate valve the movable plate assembly is guided to move in a cover secured to the housing. Thus, for example, in a slide gate valve described in DE-OS No. 21 61 368, a cover is hinged to swing out from a housing which supports a movable plate assembly for movement and which, in the operating position, is secured to the housing, preferably by four bolts.
In another slide gate valve disclosed in West German Pat. No. 32 08 101, a movable plate assembly is guided on guide ribs which are bolted to side walls of a housing. After loosening of tensioning means that press a sliding plate against a bottom plate and removal of the guide ribs, the movable plate assembly can be removed from the housing. In another modification, the housing is provided with a removable end wall, after the removal of which and the loosening of the tensioning means the movable plate assembly can be removed.
During operation, the slide gate valves are often disassembled even after one or two ladle teeming operations for maintenance purposes or for the replacement of eroded refractory plates. Therefore, in the case of the above-mentioned slide gate valves, the aforementioned bolts must each time be loosened and the movable plate assembly removed from the housing and be appropriately reassembled. Since during maintenance work such slide gate valves are generally heated to very high temperatures and become fouled, manual disassembly is relatively cumbersome. Also, the assembly must be carried out with proper care, because the adjusting bolts, which must usually be secured with a torque spanner, must be set with precision.